The present disclosure relates to a multilayer ceramic electronic component and a board having the same.
Electronic components using a ceramic material include capacitors, inductors, piezoelectric elements, varistors, thermistors, and the like.
Among ceramic electronic components, multilayer ceramic capacitors (MLCCs), having advantages such as compactness, guaranteed high capacitance, and ease of mountability, may be used in various electronic devices.
For example, MLCCs may be used as chip-type condensers installed on the printed circuit boards (PCBs) of various electronic products such as imaging devices (or video display apparatuses) including liquid crystal displays (LCDs), plasma display panels (PDPs), and the like, as well as computers, personal digital assistants (PDAs), cellular phones, and the like, to charge or discharge electricity.
The MLCC may have a structure in which a plurality of dielectric layers and internal electrodes, the internal electrodes having opposing polarities, are alternately disposed between the dielectric layers.
Here, the dielectric layers have piezoelectric properties, and thus, when a direct current (DC) or alternating current (AC) voltage is applied to an MLCC, a piezoelectric phenomenon may occur between internal electrodes, expanding and contracting the volume of a ceramic body according to frequencies to generate periodic vibrations.
Such vibrations may be transferred to a board through external electrodes of the MLCC and solders connecting the external electrodes and the board, inducing the entirety of the board to act as an acoustically radiating surface to emit vibratory sound as noise.
Such vibratory sound may correspond to audio frequencies ranging from 20 Hz to 20000 Hz, causing listener discomfort, and such vibratory sound, causing listener discomfort, is known as acoustic noise.
In this regard, as electronic devices used with mechanical components tend to be reduced in terms of noise generation, acoustic noise generated by an MLCC may be more often perceived by listeners.
When an operating environment of a device is significantly noise-free, a user may consider acoustic noise to be abnormal, recognizing it as a fault of the device.
In addition, in a device having a voice communications function, acoustic noise overlapping audio output may degrade quality of the device.